Over the next stretch of time, Zhang Xiao tested several more common spells to increase his sample size.
The results were much the same.
The Knockback Jinx, for example, underwent a curious change when he shouted it in Chinese.
"Back! Back! Back!" became three consecutive blasts with astonishing power. That might also have had something to do with the image in his mind as he shouted, jabbed his wand, and stamped his feet.
The ranking was still "native language" > loud incantation > quiet muttering > Nonverbal Spell.
No wonder so many wizards shouted their incantations when dueling or in certain other situations, even though they were proficient in Nonverbal Spells and could cast them with considerable power.
For them, shouting an incantation meant "native language + loud incantation," which was a substantial boost.
So what determined the power of a Nonverbal Spell? Proficiency or understanding? Zhang Xiao pondered it for a while but came up with nothing. After all, this was sixth-year material.
The safest option was to find a chance to ask Professor Flitwick when the Charms Club met. That kindly professor probably would not hold anything back.
Zhang Xiao held his chin and examined his record sheet. Hmm... these were all fairly benign spells. There was no dark magic or anything of the sort.
If he had the chance, he should learn about one or two less dangerous forms of dark magic. With Bird Sis there to keep him in check, he probably would not get sucked in.
Still, dark magic seemed to operate on different principles from benign spells. Its power was outrageously high.
Back in her first year, Daphne Greengrass had been at school for less than a month, yet the dark magic passed down in her family had already packed as much power as